Joaquín “El Chapo” Guzmán and Alfredo Beltrán-Leyva were friends and relatives by marriage — until they became bitter enemies. They worked together to become two of Mexico’s most powerful drug lords, then they went to war with each other. Now the years-long saga between the pair has taken a peculiar new turn: They have the same lawyer.

With Chapo awaiting trial in Brooklyn early next year on a slew of conspiracy charges, he’s hired a lawyer who recently defended Beltrán-Leyva in a very similar battle with the Justice Department. Beltrán-Leyva was sentenced in April to life in U.S. federal prison after pleading guilty to distributing multiple tons of cocaine and meth. The same fate could await Chapo if he’s convicted.

The lawyer, Angel Eduardo Balarezo, officially became Chapo’s private counsel September 3, and he’s in the midst of a month-long handoff of the case with the public defenders who have controversially represented the purported billionaire at taxpayer expense since he was extradited from Mexico in January. Balarezo is set to take over entirely on October 2, and he’s expected to be joined by Jeffrey Lichtman, another attorney Chapo has on retainer who is famous for defending New York City mob boss John Gotti Jr.

READ: We talked to El Chapo’s lawyer about defending a notorious drug lord

Balarezo took the job despite the possibility that U.S. authorities could try to confiscate his paycheck. Prosecutors are trying to seize $14 billion worth of assets from Chapo, the estimated value of the drugs he’s accused of smuggling over the years. The Justice Department initially tried to take $10 billion in drug money from Beltrán-Leyva, but Balarezo persuaded a judge to lower the demand to $529 million after arguing the initial figure was “pulled from thin air.” The payment issue has been a point of contention in Chapo’s case, with the government simultaneously arguing that he shouldn’t have a public defender while refusing to promise not to take any funds paid to private lawyers.

“I made an educated decision that I will get paid for my services,” Balarezo told VICE News. “Obviously, nobody wants to work for free. I made a decision, I reviewed the law, reviewed what the situation was, and decided I’d go for it.”

Prosecutors could potentially raise objections to Balarezo’s involvement with Chapo due to his handling of the Beltrán-Leyva case. The prosecution previously argued that the public defenders assigned to Chapo had a conflict of interest because other lawyers in their association briefly represented other drug traffickers who are tangentially involved in the case. Beltrán-Leyva is much more closely tined with Chapo, and Balarezo filed a letter to the court under seal on September 6 titled “Concerning Possible Conflict of Interest.”

“I can’t really go into it, [the letter] was filed under seal for a reason,” Balarezo said. “My representation of Alfredo Beltrán-Leyva doesn’t implicate this case at all. Mr. Beltrán is not cooperating and doesn’t intend to cooperate, so there should be no conflict.”

READ: El Chapo’s lawyers say he’s super-polite and won’t try another escape

A spokesman for the U.S. Attorney’s office for the Eastern District of New York declined to comment. Michelle Gelernt, one of Chapo’s attorneys from the Federal Defenders, said she doesn’t believe Balarezo’s past relationship with Beltrán-Leyva poses a conflict.

Balarezo, who is based in Washington, D.C., has experience defending drug lords, most notably Zhenli Ye Gon, a Chinese-Mexican businessman caught in Mexico City with more than $200 million in U.S. currency. Ye Gon was suspected of importing chemicals used to manufacture meth and laundering cartel money, but the charges against him were dismissed and he was shipped back to Mexico last October.

Balarezo argued that his past involvement with Beltrán-Leyva is actually an advantage, since the cases are so similar, to the point that “some of the alleged [drug] loads that were Mr. Guzmán’s were previously Mr. Beltrán’s and his family’s.”

“I believe there is going to be some overlap of witnesses,” Balarezo said. “It gave me a preview, I would say, of what the government’s case may look like against Mr. Guzmán.”

Chapo and Beltrán-Leyva both hail from the same municipality in the fertile hills of Sinaloa, in the heart of the Golden Triangle region has long supplied American consumers with heroin and marijuana. Chapo went on to lead the Sinaloa cartel, while Alfredo was one of five brothers behind the Beltrán-Leyva Organization or BLO.

Chapo and the Beltrán-Leyva brothers — chiefly Alfredo and his older siblings Arturo and Hector — came up together through the ranks of the Mexican drug trade in the early ‘90s, eventually forging an “Alianza de Sangre” or blood alliance that united Sinaloa’s most powerful narcos in what became known as The Federation. Alfredo, known as “El Mochomo” or the Desert Ant, helped seal the deal by wedding one of Chapo’s cousins.

READ: El Chapo’s lawyer says jail for him is worse than for anyone else in the U.S.

The downfall began in 2008. A few months after Alfredo was captured by Mexican authorities, Chapo’s son Archivaldo was released from prison on a technicality, leading the Beltrán-Leyvas to suspect they’d been betrayed. Led by Arturo Beltrán-Leyva — nicknamed “El Jefe de Jefes” or The Boss of Bosses — the gang splintered away from Chapo and declared all-out war, starting with an ambush that killed one of Guzmán’s sons. Arturo was gunned down in 2009 during a shootout with Mexican marines. Hector Beltrán-Leyva was arrested in 2014.

Alfredo was extradited to stand trial in Washington, D.C., and he eventually admitted to coordinating massive cocaine shipments and running “multiple methamphetamine laboratories” in Sinaloa, though he insists his brother Arturo was in always charge. The Beltrán-Leyva family’s business was so closely linked with Chapo that Arturo is named as the lead defendant in his indictment, and the case against him in Brooklyn is officially titled “USA v. Beltrán-Leyva et al.”

A severely weakened version of the Beltrán-Leyva Organization still operates in parts of Sinaloa, now led by Alfredo’s son, “El Mochomito,” who is also Chapo’s nephew. The bad blood between the families still lingers. El Mochomito has reportedly formed an alliance with a rival cartel from the nearby state of Jalisco and started encroaching on Chapo’s old turf in Sinaloa, including his hometown. Chapo’s sons are believed to be running the operation he left behind — presumably without their father’s help, since he’s currently locked in extreme solitary confinement at Manhattan’s Metropolitan Correctional Center.

Gelernt, Chapo’s public defender, said her team has been visiting Chapo twice a day, a schedule she hopes Balarezo will maintain since “daily legal visits are really the only thing alleviating the effects of solitary confinement” on the 60-year-old kingpin.

Chapo’s private attorneys will likely continue the fight started by Gelernt over the terms of his confinement. Lichtman said he’s been delayed in officially joining Balarezo on the case in part by authorities revoking visitation rights and a travel visa for Guzmán’s sister. Chapo is due back in Brooklyn federal court on November 6.